A Systematic Literature Review of Spine Neurostimulation Therapies for the Treatment of Pain.

OBJECTIVE: To conduct a systematic literature review of spinal cord stimulation (SCS) for pain. DESIGN: Grade the evidence for SCS. METHODS: An international, interdisciplinary work group conducted literature searches, reviewed abstracts, and selected studies for grading. Inclusion/exclusion criteria included randomized controlled trials (RCTs) of patients with intractable pain of greater than one year's duration. Full studies were graded by two independent reviewers. Excluded studies were retrospective, had small numbers of subjects, or existed only as abstracts. Studies were graded using the modified Interventional Pain Management Techniques-Quality Appraisal of Reliability and Risk of Bias Assessment, the Cochrane Collaborations Risk of Bias assessment, and the US Preventative Services Task Force level-of-evidence criteria. RESULTS: SCS has Level 1 evidence (strong) for axial back/lumbar radiculopathy or neuralgia (five high-quality RCTs) and complex regional pain syndrome (one high-quality RCT). CONCLUSIONS: High-level evidence supports SCS for treating chronic pain and complex regional pain syndrome. For patients with failed back surgery syndrome, SCS was more effective than reoperation or medical management. New stimulation waveforms and frequencies may provide a greater likelihood of pain relief compared with conventional SCS for patients with axial back pain, with or without radicular pain.

Long-term Outcomes Using Intrathecal Drug Delivery Systems in Complex Regional Pain Syndrome.

OBJECTIVE: Providing durable long-term pain control for patients with complex regional pain syndrome (CRPS) is challenging. A multidisciplinary approach focused on physical therapy is frequently prescribed, with opioids and invasive procedures reserved for those challenged by functional progression. In this study, we examined the long-term efficacy of intrathecal drug delivery systems (IDDS) in patients with CRPS at our institution. METHODS: Patients with CRPS implanted with an IDDS between 2000 and 2013 who had four or more years of continuous follow-up were included in the analysis. The outcome variables of interest were pain intensity and oral opioid intake. The primary predictor of interest was dose of intrathecal opioids, with ziconotide, bupivacaine, and clonidine characterized as binary secondary predictors. RESULTS: Of the 1,653 IDDS identified, 62 were implanted primarily for CRPS-related pain. Of these, 26 had four or more years of complete follow-up data. Pain scores did not significantly decrease over time, and we observed no correlation between pain intensity and use of any intrathecal medication. Although oral opioid intake decreased over time, intrathecal opioid dose did not affect oral opioid consumption. Ziconotide was associated with a hastening of the decrease in oral opioid intake, whereas the presence of bupivacaine paradoxically increased oral opioid intake. CONCLUSIONS: Our study demonstrates that intrathecal opioid dose was not associated with long-term decreases in oral opioid intake. Additionally, ziconotide was associated with a decrease in oral opioid intake over the four-year follow-up, and bupivacaine was associated with an increase in oral opioid intake. Our study examines the long-term effectiveness of intrathecal medications in managing pain in patients with complex regional pain syndrome. We present a detailed follow-up over four years for 26 patients, tracking oral opiate intake, pain scores, and intrathecal pump settings. Our findings suggest that intrathecal opiates may not be effective in reducing oral opiate intake, ziconotide may hasten a decrease in intake, and bupivacaine may lead to an increase in intake.

Efficacy of a Targeted Drug Delivery on-Demand Bolus Option for Chronic Pain.

BACKGROUND AND OBJECTIVES: Intrathecal targeted drug delivery systems historically required physician office visits for dose adjustment to manage fluctuating pain. A wireless device now enables patients to supplement their basal intrathecal infusion with a programmed on-demand bolus dose. We sought to quantify the change in oral breakthrough opioid need associated with the use of an intrathecal bolus in comparison to those treated with the basal infusion alone. METHODS: Demographic, dosage, bolus usage and longevity data were extracted from the historical medical record of 69 patients (18/51 bolus/nonbolus) followed continuously at our center. Medication consumption and Pain Disability Index measures were obtained at baseline and most recent follow-up. RESULTS: Among patients with the bolus option, only 2 (11%; confidence interval [CI] 0% to 26%) continued to require oral opiates to manage breakthrough pain compared to 29 (57%; CI 43% to 71%) without the bolus option. The Pain Disability Index score decreased by 19% in patients with the bolus option and by 25% in those with the basal infusion. Total daily intrathecal opioid intake was 34% lower in the group with the bolus device. CONCLUSIONS: Utilizing an intrathecal bolus to treat incident pain was a safe way to manage unpredictable breakthrough pain and may represent a cost-saving opportunity by eliminating the need for oral analgesic medications.

Kyphoplasty increases vertebral height, decreases both pain score and opiate requirements while improving functional status.

Vertebral compression fractures can result from advanced osteoporosis, or less commonly from metastatic or traumatic insults to the vertebral column, and result in disabling pain and decreased functional capacity. Various vertebral augmentation options including kyphoplasty aim at preventing the sequelae of pain and immobility that can develop as the result of the vertebral fractures. The mechanism for pain relief following kyphoplasty is not entirely understood, and the restoration of a portion of the lost vertebral height is a subject of debate. We retrospectively reviewed radiographic imaging, pain relief, analgesic intake and functional outcomes in 67 consecutive patients who underwent single- or multilevel kyphoplasty with the primary goal of quantifying the restoration of lost vertebral height. We observed a mean of 45% of the lost vertebral height restored postprocedurally. Secondarily, kyphoplasty was associated with significant decreases in pain scores, daily morphine consumption and improvement in patient-reported functional measures.

Combination therapy with simultaneous delivery of spinal cord stimulation modalities: COMBO randomized controlled trial.

Aim: The Combining Mechanisms for Better Outcomes randomized controlled trial assessed the effectiveness of various spinal cord stimulation (SCS) modalities for chronic pain. Specifically, combination therapy (simultaneous use of customized sub-perception field and paresthesia-based SCS) versus monotherapy (paresthesia-based SCS) was evaluated. Methods: Participants were prospectively enrolled (key inclusion criterion: chronic pain for ≥6 months). Primary end point was the proportion with ≥50% pain reduction without increased opioids at the 3 month follow-up. Patients were followed for 2 years. Results: The primary end point was met (n = 89; p < 0.0001) in 88% of patients in the combination-therapy arm (n = 36/41) and 71% in the monotherapy arm (n = 34/48). Responder rates at 1 and 2 years (with available SCS modalities) were 84% and 85%, respectively. Sustained functional outcomes improvement was observed out to 2 years. Conclusion: SCS-based combination therapy can improve outcomes in patients with chronic pain. Clinical Trial Registration: NCT03689920 (ClinicalTrials.gov), Combining Mechanisms for Better Outcomes (COMBO).

Spinal cord stimulation (SCS) is a device-based therapy for chronic pain that delivers electrical impulses to the spinal cord, disrupting pain signals to the brain. Pain relief can be achieved using different SCS techniques that use or do not use paresthesia (stimulation that produces a tingling sensation). These approaches affect patients in different ways, suggesting that different biological processes are involved in enabling pain relief. Research also suggests that better long-term results occur when patients can choose the therapy that is best for their own needs. This clinical study compared pain relief and other functional activities in those receiving combination therapy (simultaneous use of SCS that does and does not produce tingling sensation) against those receiving monotherapy (only SCS therapy producing tingling sensation) for 3 months. In the study, 88% of those receiving combination therapy and 71% with monotherapy alone reported a 50% (or greater) decrease in overall pain (the 'responder rate') without an increased dose of opioid drugs at 3 months after the start of therapy. This responder rate was found to be 84% at 1 year and 85% at 2 years (with all SCS therapy options available). Analysis of functional activities or disability showed that patients improved from 'severely disabled' at study start to 'moderately disabled' after 2 years, indicating that effective long-term (2 year) improvement can be achieved using SCS-based combination therapy for chronic pain.

Cooled and traditional thermal radiofrequency ablation of genicular nerves in patients with chronic knee pain: a comparative outcomes analysis.

INTRODUCTION: Genicular nerve radiofrequency ablation (GNRFA) is a minimally invasive intervention for patients with chronic knee pain (CKP) not responding to conservative treatments. Few investigations have compared treatment outcomes of cooled-RFA (c-RFA) and thermal-RFA (t-RFA), two common approaches of GNRFA. This study aims to investigate and compare outcomes, including probability of treatment success, between c-RFA and t-RFA in patients with CKP. METHODS: This retrospective cohort study analyzed a total of 208 propensity score matched patients, including 104 patients who received c-RFA and 104 patients who received t-RFA. The primary outcome was probability of pain relief after the procedure, defined as reduction in Numeric Rating Scale (NRS) pain score of 2 or greater. The secondary outcomes were degree of NRS pain score reductions, duration of relief, and the probability of patients receiving TKA within 1 year of treatment. RESULTS: T-RFA was associated with a higher probability of pain relief within 1, 3, and 6 months after procedure when compared with c-RFA. Probabilities of pain relief from t-RFA and c-RFA were 62% (95% CI 51% to 71%) and 43% (95% CI 34% to 53%; p=0.01) within 1 month, 78% (95% CI 68% to 85%) and 55% (95% CI 45% to 64%; p<0.001) within 3 months, and 79% (95% CI 70% to 86%) and 59% (95% CI 49% to 68%; p<0.01) within 6 months, respectively. t-RFA was also associated with greater mean NRS pain score reduction at 1 month after procedure: -4.71 (95% CI -5.3 to -4.1) when compared with -3.59 (95% CI -4.3 to -2.9; p=0.02) from c-RFA. T-RFA and c-RFA were comparable in pain score reduction at 3, 6, 9 and 12 months after procedure. Both groups demonstrated comparable duration of relief and probability of patients receiving TKA within 1 year. DISCUSSION: Both t-RFA and c-RFA effectively reduced NRS pain scores in most patients with CKP within the 1 year follow-up period. Genicular nerve t-RFA was associated with a higher probability of treatment success and a greater degree of pain relief at 1 month after the procedure when compared with c-RFA in propensity score matched patients with CKP.

Tanezumab for chronic low back pain: a randomized, double-blind, placebo- and active-controlled, phase 3 study of efficacy and safety.

ABSTRACT: This randomized, double-blind, phase 3 study (56-week treatment; 24-week follow-up) assessed tanezumab in patients with chronic low back pain and history of inadequate response to standard-of-care analgesics (NCT02528253). Patients received placebo, subcutaneous tanezumab (5 or 10 mg every 8 weeks), or oral tramadol prolonged-release (100-300 mg/day). Primary endpoint was change in low back pain intensity (LBPI) at week 16 for tanezumab vs placebo. Key secondary endpoints were proportion of patients with ≥50% decrease in LBPI at week 16, change in Roland Morris Disability Questionnaire at week 16, and change in LBPI at week 2 for tanezumab vs placebo. Adverse events and joint safety were assessed through weeks 56 and 80, respectively. Tanezumab 10 mg met the primary endpoint by significantly improving LBPI at week 16 vs placebo; least squares (LS) mean (95% CI) difference = -0.40 (-0.76 to -0.04; P = 0.0281). Tanezumab 10 mg significantly improved all key secondary endpoints. Tanezumab 5 mg did not meet the primary endpoint (LS mean [95% CI] treatment difference vs placebo = -0.30 [-0.66 to 0.07; P = 0.1117]), preventing formal testing of key secondary endpoints for this dose. The proportion of patients with ≥50% improvement in LBPI at week 16 was 37.4% in the placebo group, 43.3% in the tanezumab 5 mg group (Odds ratio [95% CI] vs placebo = 1.28 [0.97 to 1.70; P = 0.0846]), and 46.3% in the tanezumab 10 mg group (Odds ratio [95% CI] vs placebo = 1.45 [1.09 to 1.91; P = 0.0101]). Prespecified joint safety events were more frequent with tanezumab 10 mg (2.6%) than tanezumab 5 mg (1.0%), tramadol (0.2%), or placebo (0%). Seven patients, all in the tanezumab 10 mg group (1.4%), underwent total joint replacement. In conclusion, tanezumab 10 mg significantly improved pain and function vs placebo in patients with difficult-to-treat chronic low back pain. Tanezumab was associated with a low rate of joint safety events, some requiring joint replacement.

Improving guideline compliance: assessment of unit-based reminder for monitoring platelet counts post-PCI.

In assessing our institution's vascular access site bleeding complication rate, we found (anecdotally) that for many patients platelet count was not measured according to recommendations of the manufacturer of the predominantly used glycoprotein (GP) IIb/IIIa agents, in either the catheterization recovery unit (CRU) or the coronary care unit (CCU). We hypothesized that a unit-focused effort to remind cardiologists to order platelet counts after percutaneous coronary interventions GP IIb/IIIa would improve compliance. Findings indicated that a greater number of patients had platelet counts drawn after a reminder effort had been implemented. For both the first and second draws, the CCU had a higher pre-reminder rate than the CRU. Post-reminder, the CCU had no significant changes, whereas the CRU showed significant increases in both the first and second draws. For post GP IIb/IIIa platelet measurement, aggregate analysis (CRU and CCU) showed that, of those patients who had platelet counts drawn pre-reminder, only 18.2% met the first guideline and only 17.1% met the second. Post-reminder results showed no significant changes for the first or second draws. We concluded that the practical application of a standard operating procedure can have a secondary beneficial effect despite not meeting the stringent parameters set in prescribing guidelines.